The present invention relates to a fuel injector with a piezoelectric actuator.
Fuel injectors with a piezoelectric actuator, i.e. for moving a shutter between a closed position and an open position, have been known for some years.
During operation, the piezoelectric actuator develops a certain amount of heat which, in steady operating conditions, produces a relatively high increase in its operating temperature, thus impairing its working life. To eliminate the above drawbacks, it has been proposed, e.g. as described in Patent Applications DE19909451 and DE19856202, to provide a cooling circuit for subjecting the injector casing to a continuous stream of cooling fluid (typically air or water). Such a solution, however, is relatively expensive and complicated, by requiring a cooling circuit for each injector.
It is an object of the present invention to provide a fuel injector with a piezoelectric actuator, designed to eliminate the aforementioned drawbacks, and which, in particular, is cheap and easy to produce.
According to the present invention, there is provided a fuel injector with a piezoelectric actuator, as claimed in claim 1.